dna degradation

hello,I'm working on Lisianthus (plant from the family Gentianaceae).recently I have a problem of a genomic dna degradation, the DNA was produced using chloroform-octanol it looked O.K at the begging but after a few weeks in -4 it was a complete mess. any suggestions why it could happen?what can I do to avoid it?

Did you resuspend your DNA in 10 mM tris pH 7.0-7.5 or TE buffer? If you used just water, the DNA will undergo acid hydrolysis, degrading it. Otherwise it could be that you have DNase contamination of your samples (maybe in the tubes).

Did you resuspend your DNA in 10 mM tris pH 7.0-7.5 or TE buffer? If you used just water, the DNA will undergo acid hydrolysis, degrading it. Otherwise it could be that you have DNase contamination of your samples (maybe in the tubes).

Unusual, perhaps there are some DNases coming through your extraction proceedure. It could be that there is some DNase in one of your reagents otherwise - commonly in the water used to prepare solutions.